The invention relates to a ball-joint coupling comprising a male coupling member provided with a ball and a female coupling member having a socket to receive the ball, such coupling finding particular application in the hitching of trailers or caravans to motor or other vehicles.
Prior art couplings of this kind have various disadvantages. They are noisy because of their clearances and the resulting jerks during towing or braking. In addition, they permit the trailer or caravan too much freedom, in that they do not prevent it from pitching, rolling or swaying.
Various improvements have been proposed to obviate these disadvantages, but the previously proposed means are usually expensive and provide only partial solutions to the problem. More particularly, it has been proposed to cover the ball with a rubber layer, but the prior art arrangement proposed to this end is bulky and increases the difficulty of coupling and uncoupling the female coupling member or hitch co-operating with the ball.